Plants and trees can be prone to numerous diseases and pests such as eastern spruce budworm, jack pine budworm, forest tent caterpillar, gypsy moth, Dutch elm disease, pine sawfly, pine false budworm, American chestnut blight etc. To prevent and/or control such diseases and pests there exist many appropriate treatment chemicals such as insecticides, fungicides, nutrients and growth hormones. The treatment chemicals are often sprayed on the leaves, spread on the soil at the base of the trees or injected in the root or the trunk of the trees. The latter method of directly injecting treatment chemicals into the tree is generally more efficient as well as posing less danger to the environment and will be the focus of the present specification, as an exemplary embodiment of the invention.
Injectors for injecting fluids into trees are well known. Mauget, in U.S. Pat. No. 4,365,440, issued Dec. 28, 1982, discloses a device wherein a discharge tube is inserted into a tree. A container containing treatment chemicals is then connected to the discharge tube thereby puncturing a container wall and allowing the treatment chemicals to flow from the container to the discharge tube and into the tree. To force the treatment chemicals into the tree, opposite ends of the container are required to be grasped and pressed. A disadvantage of this apparatus is that is requires that an operator be present with the injection device during the duration of the injection.
Doolittle, in U.S. Pat. No. 5,239,773, issued Aug. 31, 1993, discloses a tree injection device. Mounted on the injection device is a needle having a front end, an opposite end adapted for attachment to a source of pressurized liquid and a generally wedge-shaped free-end portion having top and bottom surfaces tapering to a thin edge across the free-end to facilitate penetration into the tree trunk. The needle of the apparatus is then inserted into the stem or trunk of a plant to inject liquid into the stem or trunk of the plant. A disadvantage of this device is again that it requires that an operator be present with the injection device during the length of the injection.
Eldridge in U.S. Pat. No. 5,956,894, issued Sep. 28, 1999, also discloses a tree injection apparatus and method for using it. Wild et al. in U.S. patent application No. 2002/0046486A1, published Apr. 25, 2002, discloses a woody plant injection method and apparatus. Here also, a disadvantage is that an operator must be present with the injection apparatus during the duration of the injection.
Many injection devices exist in fields outside the field of tree injection, particularly in the field of Surgery. For example, U.S. Pat. No. 4,394,863, issued Jul. 26, 1983 and U.S. Pat. No. 4,723,937, issued Feb. 9, 1988 both disclose automatic medicament injecting syringes. In both cases, the insertion of a hypodermic needle into a patient and the injection of medication are accomplished automatically by a spring force in response to a simple actuation. Fluid release is not, however, initiated by coupling to a nozzle. Nor are such devices designed to effect injection against a substantial back-pressure. Further, such injection devices would not be amenable to the field of tree injection for at least the concerns regarding the relative fragility of a needle being inserted into a tree.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principle of the invention, and the manner of its implementation. The invention in its broadest and more specific forms will then be further described, and defined, in each of the individual claims which conclude this specification.